Here are a few details about metering key program files.
Metering predefined key program files
If a software component has a predefined key program file (because the software component is associated to the predefined software product), the key program file is automatically listed in ECV, in the "Software Product" dialog box, on the "Meter/track usage" tab, and can be automatically metered together with the metered software component.
If you delete the predefined key program file in the "Software Product" dialog box, at "Meter/track usage" > "Add Program", the NS.Nightly task will re-associate the file with the software component.
As Andrew has already said, currently there is no option to remove predefined key program files from metering together with the relevant metered and predefined software product.
Metering other key program files
On the "Meter/track usage" tab, you can add some other key program file to a software component (the software component can be associated to the predefined software product or any other product). And if you wish, the program file will be automatically metered together with the metered software component.
However if you delete the key program file that you have added, the NS.Nightly task will not re-associate the file with the software component.
For example, in the Adobe Reader 9 product (predefined and metered), the predefined key program file is AcroRd32.exe, and another key program file, added by you, is AcroRd32Info.exe. If you remove both key program files on "Meter/track usage" tab, and then run the NS.Nightly task, only AcroRd32.exe will be still metered with Adobe Reader 9.
You can find more information in the topic about the NS.Nightly task at the following URL: http://www.symantec.com/docs/HOWTO63581